The invention relates to apparatus for harming or killing fouling flora or fauna and an item carrying the same.
Fouling of items placed in the water, such as boat hulls, is a well known problem. The fouling problem is usually combated by the use of a toxic, anti-fouling paint which should kill animal or plant life which attaches itself to the painted surface. The use of toxins in this way is environmentally undesirable and other methods of control or elimination of fouling have been investigated. One such method is described in International patent application no. WO92/17061 in the name of the present applicant. The disclosure of that prior document is incorporated herein by reference. WO92/17061 discloses a trap for swimming larvae such as the larvae of fresh water mussels. The trap comprises two metal plates which are coated with insulating material and spaced apart in fresh water. The plates are connected to a high voltage AC generator to provide an electric field across the plates. Fresh water has low conductivity and so the leakage current between the plates is low. As the polarity of the water around a larvae changes, the induced polarity of the body liquid of the larvae also changes and this is sufficient to disable or kill the larvae relatively quickly. More than 90% of the internal content of a larvae is highly conductive aqueous liquid.
Providing two insulated conducting plates closely spaced apart so that larvae can swim between them may be relatively difficult to achieve.